The present invention relates to a system for driving information carrying members in a sewing machine.
In the conventional sewing machines, the timing to determine the position of lateral oscillation of a needle and the timing to operate a feed regulator have a substantially 180.degree. phase difference in the rotation angle of a main shaft, so that it is necessary to drive a bight information carrying member and a feed information carrying member synchronously with rotation of the main shaft while maintaining the fixed phase difference. Therefore, in the sewing machine of the type that drives the two information carrying members by means of step motor, the structure is so composed that one step motor is employed for each of the information carrying members and the two motors are driven by individual control means respectively, as disclosed in U.S. Pat. No. 4,103,632. However, this structure brings about an increase of the production cost in practical manufacture of such sewing machine, and there also exists technical difficulty of installing the two step motors with the information carrying members within a limited space of the sewing machine frame. Thus, satisfactory solutions of these problems must be found to realize household sewing machines equipped with step motors.